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Author Topic: Possible Issue with first lower I milled  (Read 1224 times)

badgenes

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Possible Issue with first lower I milled
« on: August 29, 2016, 10:39:26 AM »

I'm new to all of this and would appreciate any input prior to live testing.  This is the only AR-15 I have access to so I don't have any frame of reference beyond the Internet.  I milled and drilled my first at lower and during assembly found that I could not quite insert safety selector with the hammer cocked.  The amount of rear trigger assembly intruding in the selector hole was small but enough to cause the selector to stop.  Selector inserts fine with trigger group removed, albeit snugly.  Just on a lark, I decided to improvise and insert the selector first, angle it to 1 o'clock position and slide the trigger group in under it.  I completed assembly and test trigger function, all seems to work as described in various assembly and testing guides.  The safety functions correctly as well, albeit feeling very snug.  The only thing of note is that the trigger is tight, doesn't travel very far to release the hammer.  I've tested this repeatedly with a block, then with the rifle fully assembled.  My only concern is that something go wrong during live fire. 

My pocket is ~ 1.22 inches deep, all else is spec.  I'm using an old set of calipers though, so I could be 1.21 or 1.24 depending upon their accuracy (and my ability to read them with my over 40 eyes). 

I appreciate any thoughts or advice you may have.
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Jefe

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Re: Possible Issue with first lower I milled
« Reply #1 on: August 29, 2016, 01:50:35 PM »

That sounds pretty standard. You can put the trigger in first or the safety in first. Sometimes I can do one but not the other and that's with various lowers and triggers, not just 80% lowers.

Welcome to the forum!
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nodixe

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Re: Possible Issue with first lower I milled
« Reply #2 on: February 11, 2017, 03:15:14 PM »

I've done about 10 of these now so I'm not an expert but the most common problem I have is it not being deep enough. I always make sure its at least 1.240 inches deep. If its out of spec I believe it will just bind. As long as it works dry firing (protect the wall in front of hammer!) then it should be fine. Add some oil to all the moving parts and cycle the hammer cock/trigger pull a buncha times and should be good to go....should be....
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helidude350

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Re: Possible Issue with first lower I milled
« Reply #3 on: February 12, 2017, 02:34:30 AM »

what brand trigger group are you using?
Which jig? Lower?

I had an early one that would not function with an Anderson fcg, but switched with another brand and functioned just fine. ( not a problem with the trigger quality).
Either the pocket was shallow, or my pin holes were too low, I don't recall.

The hammer trigger relationship is most important. Selector to trigger is second.

I have also had a misaligned trigger hole that wouldn't let the trigger have full travel.



any one of those or combination could cause that.

Also check to see if the hammer is square it the upright position. I had one that wouldn't always fire or reset. It was leaning a degree or two to the left. So depending where the bcg settled it cleared sometimes, or would interfere with the hammer.    Dremmeled a little off that side and good to go. ( trigger to hammer was square or I would have scrapped it.)


If all works out, you might drop the trigger in, leave it unpinned, insert the selector, then pin the trigger.


Another option for bad holes could be a drop in fcg like a Taccon, CMC, Timminey etc.
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